title: Identifying neuropathic back and leg pain: a cross-sectional study.
abstract: Low back pain is a widespread debilitating problem with a lifetime prevalence of 80%, with the underlying pain mechanism unknown in approximately 90% of cases. We used the painDETECT neuropathic pain screening questionnaire to identify likely pain mechanisms in 343 patients with low back pain with or without leg pain in southeastern England referred for physiotherapy. We related the identified possible pain mechanisms nociceptive, unclear, and neuropathic to standardised measures of pain severity (Numeric Rating Scale), disability (Roland Morris Low Back Pain Disability Questionnaire), anxiety and depression (Hospital Anxiety and Depression Scale), and quality of life (Short Form 36 Health Survey Questionnaire Version 2). In addition, we investigated any relationship between these possible pain mechanisms and leg pain, passive straight leg raise, and magnetic resonance imaging evidence confirming or eliminating nerve root compression. A total of 59% of participants (n=204) reported likely nociceptive pain, 25% (n=85) unclear, and 16% (n=54) possible neuropathic pain. The possible neuropathic pain group reported significantly higher pain, disability, anxiety, and depression, reduced quality of life and passive straight leg raise compared to the other pain groups (P<.05). A total of 96% of participants with possible neuropathic pain reported pain radiating to the leg (76% below the knee); however, leg pain was still more common in patients with nociceptive pain, suggesting that leg pain is sensitive to, but not specific to, possible neuropathic pain. No relationship was demonstrated between possible neuropathic pain and evidence for or absence of nerve root compression on magnetic resonance imaging scans. These findings suggest possible neuropathic pain is less common in low back pain patients referred through primary care and clarifies the usefulness of clinical tests for identifying possible neuropathic pain.
authors.affiliation: Head of School of Rehabilitation Sciences, Faculty of Health and Social Care Sciences, St. George's University of London/Kingston University, Cranmer Terrace, London SW17 0RE, UK Physiotherapy Department, Maidstone and Tunbridge Wells NHS Trust, TN2 4QJ, UK Physiotherapy Department, Brighton and Sussex University Hospitals NHS Trust, BN2 3EW, UK Physiotherapy Department, NHS West Sussex Primary Care Trust, BN12 6BT, UK.
authors.forename: Iain D
authors.initials: ID
authors.lastname: Beith
authors.forename: Andrew
authors.initials: A
authors.lastname: Kemp
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kenyon
authors.forename: Matthew
authors.initials: M
authors.lastname: Prout
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Chestnut
mesh_terms: D003430:Cross-Sectional Studies; D006801:Humans; D007866:Leg; D017116:Low Back Pain / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D009437:Neuralgia / Q000175:diagnosis* / Q000473:pathology*; D010147:Pain Measurement; D011320:Primary Health Care / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires